Sealed bearing roller cone drill bits generally incorporate a compensating mechanism to limit the pressure differential between the lubricant sealed within the drill bit and the well bore fluid. The most common device is a flexible diaphragm separating the two fluids. The diaphragm responds to the conditions in the well to maintain a balanced pressure across the primary dynamic seals in the drill bit. These devices also typically compensate for volumetric changes of the lubricant which occur in the form of leakage or through thermal expansion.
Conventional compensators tend to bleed lubricant during lubrication of the drill bit due to the pressure at which lubricant is pumped into the drill bit, among other factors. As a result, a drill bit may have undesirable pressure variation and/or an improper amount of lubricant. Accordingly, it is a desire to provide an apparatus and method for providing a proper quantity of lubricant into a drill bit.